The metabolic syndrome (MetS) is a co-occurrence of several medical conditions. The high prevalence of MetS, visceral obesity (i.e. excessive fat accumulation in the abdomen) with associated high blood pressure, dyslipidemia and high blood glucose, is a major threat to people health, being associated with a substantial decrease in health-related quality of life.
According to WHO (World Health Organization), OECD (Organization for Economic Cooperation and Development) and the WHF (World Heart Federation), 30-80% of the adult population in the European Region is overweight (has a body mass index (BMI) over 25). The average BMI for the European population is nearly 26.5 and obesity (BMI over 30) affects up to a third of its adult population. This means that about 130 million of the 400 million European adults are overweight or obese. Moreover, childhood obesity is an acute health crisis. About 20% of children are overweight, and a third of these are obese.
MetS is a complex of lifestyle based diseases that consists of several correlated risks of metabolic origin. In addition to dyslipidemia, hypertension and hyperglycemia, the syndrome carries a proinflammatory state. Subjects affected by the MetS are at increased risk for cardiovascular disease (2-fold), type 2 diabetes (5-fold), respiratory failure, gallbladder disease, certain types of cancer and psychosocial problems.
MetS is a diet-related disease and it is believed that MetS could be prevented by applying a correct lifestyle and diet.
Although it is generally agreed that first-line clinical intervention for the metabolic syndrome is a lifestyle change, this is insufficient to normalize the risk factors in many patients, and so residual risk could be high enough to justify drug therapy.
However, at present there are no approved drugs that can reliably reduce all the metabolic risk factors over the long term, and so there is growing interest in therapeutic strategies that might target multiple risk factors more effectively, thereby minimizing problems with multiple assumption of drugs for prolonged periods of time.
Lignans are a group of compounds found in fiber-rich foods such as cereals, oilseed, nuts, vegetables (brassica) and fruits (berries), typically regarded as components of healthy diets.
They are expected to have beneficial effects in humans after fermentative conversion in the colon, producing enterolactone and enterodiol, favorably influencing metabolic parameters related to the MetS. Subpopulations with higher consumption of lignans display considerable lower disease frequency.
A few randomized controlled studies have shown beneficial effects of diets supplemented with lignan-rich seeds (oilseeds) in the control of metabolic diseases such as dyslipidemia and type 2 diabetes. Studies have also been conducted in animal models, in which partially purified lignan fractions improved blood lipids, enhanced glycemic control and improved type 1 and type 2 diabetes.
A few in-vitro studies have also been performed to identify the lignans as antioxidants, phytoestrogens and modulators of nuclear receptors.
A recent study (Biasotto G. et al., “Oilseeds ameliorate metabolic parameters in male mice, while contained lignans inhibit 3T3-L1 adipocyte differentiation in vitro”, European Journal of Nutrition, 2014) illustrated the amelioration of metabolic parameters in male mice fed with high quantity of whole sesame and flaxseeds (20% w/w in the food), two of the most lignan-rich food sources, containing about 1% by weight of total lignans. Sesame extracts mainly comprise sesamin (SES) and pinoresinol (PIN) lignans, while flaxseeds extracts mainly comprise secoisolariciresinol (SEC) lignan. 7-hydroxymatairesinol (HMR) is only present in minor amount in sesame extracts and is not present at all in flaxseeds extracts.
HMR is the main single component of lignans in Norway spruce (Picea abies), reaching a concentration of about 60 percent of total lignans, which occurs mainly in unconjugated free form.
Lignan concentration in thick roots is 2-3 percent. Abundance of lignans occur in the heartwood of branches (5-10 percent) and twists, especially in the knots, where the amount of lignans may be higher than 10 percent. These concentrations are about hundred-fold compared to ground flaxseeds powder known as lignan-rich material.
WO00/59946 and U.S. Pat. No. 6,451,849 disclose the use of HMR for prevention of cancers, certain non-cancer, hormone dependent diseases and/or cardiovascular diseases.
WO2006/072647 discloses the use of HMR for preventing or alleviating of symptoms relating to estrogen deficiency in an individual, such as menopausal or postmenopausal symptoms, climacteric symptoms, hot flushes, vaginal dryness, vaginal atrophy, atrophy of the lower urinary tract, loss of bone mineral content, menopausal vasomotor symptoms, mood swings, insomnia, osteoporosis or any other menopause associated condition.